Improvement in hot-air furnaces



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Letters Patent No. 93,675, dated August 17, 1869.

MPROVEMENT IN HCT-AIR FURNACES The Schedule referred to theseLetters-Patent and making part of the sam'e.

To all whom it may concern.'

Be it known that I, Josnrn E. CHAPMAN, of Gannon Falls, in the county ofGoodhue, and State of Minnesota, have invented a new and usefulImprovement in Hot-Air Furnaces; and I do hereby declare that thefollowing is a full, clear, and exact description thereof, which willenable others skilled in the 'ait to make and use the saine, referencebeing had to the accompanying drawings, forming part of thisspecification.

This invention relates to a furnace for heating air for warmingbuildings, or for other purposes, and consists in the arrangement ofair-dues in the furnace 'or fire-box, and also in the hot-air vdrum orradiator, and also in the method of preventing the radiation of` heatfrom the furnace-walls, and from vthe casing thereof,l

as will be hereinafter more fully described.

In the accompanying sheet of drawingsd Figurel represents a sectionalside'elevation, showing the position of the air-tubes in the fire-box',and the forni of the radiator with the tubes therein, the section beingthrough the line :n a: of iig. 2.

Figure 2 isa cross-section of hg. l, through the line y y.

Similar letters of reference indicate corresponding parts.

A is the jacket or casing by which the furnace is surrounded. Y

rIhisis covered on the outside with a coating of plaster of Iaris, B, toprevent the radiation of heat therefrom. l

C represents the walls of the furnace, the outer sides of which are alsoprotected by a coating of plas-- front end of the furnace with the spaceJ at the back end. l

It will be seen that these air-tubes are exposed to the direct action ofthe ire, but as there is a current of air from -the outside constantlypassing through them, the heat will not be so intense as to injure them,but should the sides most exposed bec-ome injured, they ina-y beturnedover or renewed, and be replaced with others without difiiculty.

The radiator G is formed of two chambers, K andv L, connected togetherby four (more or less) large tubes, fm., through which air-tubes 1Lpass, also connecting th e front air-space' e with the space J, asbefore stated.

The smoke and gaseous products of -combustion pass up through theconnection H, into the chamber L and around the tubes n, and aredischarged through the iiue O.

"he air which enters from the top at P, and also that which passesthrough the tubesl I and n, is discharged frorn the central aperture It,and distributed therefrom, as may be desired.

S represents a damper, by closing which the heated products-ofcombustion are thrown through all the tubes m. v

Ihe furnace may be made of either sheet or 'castiron, and the parts maybe secured together in any suitable and substantial manner.y

Having thus described my invention, g

I claim as new, and ydesire to secure `by Letters Patent- 1. Protectingthe walls O of a hot-air furnace and the ,casing A by a vcoating ofpla-stervof Paris, or its equivalent', substantially as and for thepurposes de-v scribed.

2. The combination, in ahot-air furnace, of the ire.

box F, with lits tubes I and the radiator G, with its tubes m and -narranged substantially as described.

JOSEPH E. CHAPMAN. IVitnesses:

WILLIAM P. Tannen, E. ELLswonfrH.

